False

Formula for calculating monthly interest payment in amortised loans is given as:

P= (r*PV)/(1-(1+r)^-n); where P is monthly payment, r is interest rate per period, PV is loan amount and n is number of periods.

From the calculated monthly payment, monthly interest is outstanding principal times rate divided by time. The Outstanding Principal changes every month, as some portion of the monthly payment goes towards repayment of principal.